sand
oxygen
gold
carbon dioxide
helium
carbon
rust
seawater
1. Name the two metals
2.Name a gas that is not an element
3.Name a mixture
4.Name a non metallic element that is a solid .
Answer:
1. gold and rust
2. carbon dioxide
3. sea water
4. carbon
Answer:
1. Gold and Iron
2. Helium
3. Seawater
4.Rust
Explanation:
(3) 25.0 g of NaCl and 100. g of H2O
(4) 25.0 g of NaNO3 and 100. g of H2O
Answer:
2
Explanation:
Because if look at the Solubity curves you will notice other three doesn't go 25 grams. They start above the 25 grams.
Answer:
Explanation:
% of C = 35.5
Molar mass of C = 12.0107 g/mol
% moles of C = = 2.95569
% of H = 4.8
Molar mass of H = 1.00784 g/mol
% moles of H = = 4.76266
% of N = 8.3
Molar mass of N = 14.0067 g/mol
% moles of N = = 0.59257
% of Na = 13.5
Molar mass of Na = 22.989769 g/mol
% moles of N = = 0.58721
% of O = 37.9
Molar mass of O = 15.999 g/mol
% moles of O = = 2.36889
Taking the simplest ratio for C, H, O, N, Na and O as:
2.95569 : 4.76266 : 0.59257 : 0.58721 : 2.36889
= 5 : 8 : 1 : 1 : 4
The empirical formula is =
Molecular formulas is the actual number of atoms of each element in the compound while empirical formulas is the simplest or reduced ratio of the elements in the compound.
Thus,
Molecular mass = n × Empirical mass
Where, n is any positive number from 1, 2, 3...
Mass from the Empirical formula = 12*5 + 1*8 + 14 + 23 + 16*4 = 169 g/mol
Molar mass = 170 g/mol
So,
Molecular mass = n × Empirical mass
170 = n × 169
⇒ n ≅ 1
The molecular formula =
Answer : The molecular formula of a compound is,
Solution :
If percentage are given then we are taking total mass is 100 grams.
So, the mass of each element is equal to the percentage given.
Mass of C = 35.5 g
Mass of H = 4.8 g
Mass of O = 37.9 g
Mass of N = 8.3 g
Mass of Na = 13.5 g
Molar mass of C = 12 g/mole
Molar mass of H = 1 g/mole
Molar mass of O = 16 g/mole
Molar mass of N = 14 g/mole
Molar mass of Na = 23 g/mole
Step 1 : convert given masses into moles.
Moles of C =
Moles of H =
Moles of O =
Moles of N =
Moles of Na =
Step 2 : For the mole ratio, divide each value of moles by the smallest number of moles calculated.
For C =
For H =
For O =
For N =
For Na =
The ratio of C : H : O : N : Na = 5 : 8 : 4 : 1 : 1
The mole ratio of the element is represented by subscripts in empirical formula.
The Empirical formula =
The empirical formula weight = 5(12) + 8(1) + 4(16) + 1(14) + 1(23) = 169 gram/eq
Now we have to calculate the molecular formula of the compound.
Formula used :
Molecular formula =
Therefore, the molecular of the compound is,